Near-infrared photothermal molecule, preparation method thereof and application of near-infrared photothermal molecule in light-responsive polyimide material

Abstract

The application discloses a near-infrared photothermal molecule, a preparation method thereof and application of the near-infrared photothermal molecule in a light-responsive polyimide material. The structure of the near-infrared photothermal molecule is shown in the following formula. The light-responsive polyimide material is prepared by designing the photothermal molecule with a donor-acceptor-donor configuration, which can not only avoid the agglomeration phenomenon of inorganic particles doped in the polymer, well maintain the mechanical properties of the original polymer, but also realize the high-efficiency non-radiation transition ability of the photothermal molecule in the polymer. The obtained light-responsive polyimide material has an extremely fast response speed to infrared light and realizes reversible response. When the light-responsive polyimide material is irradiated by near-infrared light, the light-responsive polyimide material immediately produces a sharp deformation. After the near-infrared light is turned off, the light-responsive polyimide material almost restores to the original shape.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light-driven materials, in particular to a near-infrared photothermal molecule, a preparation method thereof and application thereof in a light-responsive polyimide material. BACKGROUND

[0002] Stimuli-responsive materials can change their shape, color or motion state under external environmental stimuli such as humidity, light, heat, pH or magnetic field, and therefore have broad application prospects in the fields of sensors, artificial muscles and soft robots. Among various stimuli sources, light is an ideal choice for driving responsive materials because it is easy to control the wavelength, intensity and polarization direction, and can achieve non-contact energy transmission. Especially since the 21st century, with the rapid development of bionic technology and artificial intelligence, intelligent polymer materials with light-induced deformation ability have become an international research hotspot. Traditionally, by introducing azobenzene groups into the main chain or side chain of a polymer, the material can be macroscopically deformed by using the trans-cis isomerization induced by ultraviolet light. Such materials have been widely used in the construction of intelligent deformation systems. However, ultraviolet light driving has the disadvantages of low biological safety, poor tissue penetration and easy to cause material photoaging, and the driving rate is relatively slow, which limits its application in biomedical and deep driving.

[0003] In recent years, near-infrared light-driven materials have gradually become a research focus due to their good biocompatibility, deep tissue penetration ability and low risk of photo-damage. Near-infrared light is almost harmless to biological tissues and can be safely used in in vivo environments, such as targeted drug delivery and endoscopic robots. Its scattering and absorption in polymers and biological tissues are weak, and it can penetrate centimeter-level depth, which is much better than ultraviolet light that can only penetrate micrometer-level depth. In addition, the low energy of near-infrared light makes it less likely to cause material degradation, which helps to improve the service life and operational safety of the device.

[0004] Currently, the common method to achieve near-infrared light response is to introduce inorganic photothermal components (such as gold nanoparticles, carbon nanotubes or graphene) into the polymer to introduce photothermal function. However, such composite materials often face problems such as uneven dispersion of inorganic particles, easy agglomeration and poor interfacial compatibility, which leads to a decrease in mechanical properties of the material and limits the efficiency of photothermal response, and easy fatigue damage in cyclic use.

[0005] Therefore, it is urgent to develop a new type of near-infrared photothermal material that can be used to prepare near-infrared light-responsive polyimide intelligent materials with fast response speed, good stability and suitability for deep driving, to meet the urgent needs of high-performance light drivers in the fields of soft robots and other frontier fields. SUMMARY

[0006] To overcome the shortcomings of the existing technology, the present invention aims to provide a near-infrared photothermal molecule and a near-infrared photoresponsive polyimide material with extremely fast response speed.

[0007] This invention is achieved through the following technical solution:

[0008] This invention provides a near-infrared photothermal molecule, the structure of which is shown in the following formula:

[0009] ;

[0010] R1 and R2 are each independently selected from the following groups: C5-C 20 Straight-chain alkyl, C5-C 20 Branched alkyl groups, C5-C 20 A cyclic alkyl chain in which carbon atoms are substituted by one or more of oxygen atoms, sulfur atoms, nitrogen atoms, alkenyl, alkynyl, aryl, carbonyl, hydroxyl, amino, carboxyl, cyano, nitro and ester groups, and a alkyl chain in which hydrogen atoms are substituted by one or more of fluorine atoms, chlorine atoms, bromine atoms and iodine atoms.

[0011] R3, R4, R5, and R6 are each independently selected from hydrogen, deuterium, halogens, and C1-C. 30 Alkyl, C1-C 30 Alkoxy, C1-C 30 Thioalkyl, aryl, heteroaryl, or triphenylamine and their derivatives; wherein the alkyl, alkoxy, thioalkyl, aryl, heteroaryl, or triphenylamine and their derivatives are optionally substituted by one or more substituents, the substituents being independently selected from deuterium, halogen, cyano, nitro, amino, hydroxyl, C1-C 20 Alkyl, C1-C 20 Haloalkyl, C1-C 20 Alkoxy, C3-C 10 cycloalkyl, C6-C 18 Aryl, 5-18 heteroaryl.

[0012] Preferably, the aryl group is selected from any one of phenyl, naphthyl, anthracene, phenanthryl, pyrene, and perylene; the heteroaryl group is selected from any one of thiophene, furanyl, pyrrole, pyridinyl, pyrimidinyl, and quinolinyl; the triphenylamine and its derivatives are wherein the carbon atom is replaced by any one or more of oxygen, nitrogen, and sulfur atoms, and the hydrogen atom is replaced by deuterium, halogen, cyano, nitro, amino, hydroxyl, or C1-C... 20 Alkyl, C1-C 20 Haloalkyl, C1-C 20 Alkoxy, C3-C 10 cycloalkyl, C6-C 18 Any one or more substitutions of aryl, 5-18 heteroaryl groups.

[0013] Further, the near-infrared photothermal molecule is selected from the following structures:

[0014] , , , , , , ;

[0015] -C in the above structure represents a straight chain, a branched chain, or a cyclic alkyl chain, and the alkyl chain is substituted with one or more of oxygen atom, sulfur atom, nitrogen atom, alkenyl, alkynyl, aryl, carbonyl, hydroxyl, amino, carboxyl, cyano, nitro, and ester group. 10 H 21 , -C8H 17 , -C6H 13 , -C4H9, -C 14 H 29 all represent a straight chain alkyl.

[0016] The present application also provides a preparation method of the above near-infrared photothermal molecule, comprising the following steps:

[0017] dissolving the compound , , a deprotonating agent, a ligand, and a catalyst in an organic solvent, mixing and refluxing, and after the reaction is completed, post-treatment is performed to obtain the near-infrared photothermal molecule;

[0018] R1, R2 are each independently selected from one of the following groups: a straight chain C5-C 20 alkyl chain, a branched C5-C 20 alkyl chain, a cyclic C5-C 20 alkyl chain, an alkyl chain in which carbon atoms are substituted with one or more of oxygen atom, sulfur atom, nitrogen atom, alkenyl, alkynyl, aryl, carbonyl, hydroxyl, amino, carboxyl, cyano, nitro, and ester group, and an alkyl chain in which hydrogen atoms are substituted with one or more of fluorine atom, chlorine atom, bromine atom, and iodine atom.

[0019] R' is selected from one or more of the following groups: hydrogen, deuterium, halogen, C1-C 30 alkyl, C1-C 30 alkoxy, C1-C 30 thioalkyl, aryl, heteroaryl, triphenylamine and derivatives thereof.

[0020] Preferably, the deprotonating agent is sodium tert-butoxide or potassium tert-butoxide.

[0021] Preferably, the ligand is tri-tert-butylphosphine tetrafluoroborate, 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl, or 2-dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl.

[0022] Preferably, the catalyst is tris(dibenzylideneacetone)dipalladium(0) or palladium acetate.

[0023] The compound of the present application The compound can be obtained by purchase or self-preparation, and can be prepared by referring to the method disclosed in Chinese Patent Application CN202510199792.8.

[0024] The present application also provides application of the near-infrared photothermal molecule in the light-responsive polyimide material.

[0025] The present application also provides a near-infrared light-responsive polyimide material comprising the near-infrared photothermal molecule of the present application.

[0026] The present application also provides a preparation method of the near-infrared light-responsive polyimide material, comprising the following steps:

[0027] The imide ring-containing dimercapto monomer and the imide ring-containing dialkynyl monomer are dissolved in the organic solvent I, and reacted at 20-80℃ for 10-360 min under a nitrogen atmosphere. After the reaction is completed, the reaction solution is introduced into methanol to precipitate the fibrous solid product. After filtration, washing and drying, the polyimide is obtained.

[0028] The near-infrared photothermal molecule is dissolved in the organic solvent I, and the polyimide is dissolved in the organic solvent II. After mixing the two solutions, the mixture is filtered through a four-fluorine filter core, and then cast or spin-coated on a substrate. The substrate is treated in a vacuum oven at 60-120℃ for 48-72 h to obtain a polyimide film doped with the photothermal molecule.

[0029] The polyimide film is placed under an ultraviolet lamp with a power density of 5 mW / cm 2 ~ 5 W / cm 2 and a wavelength of 10-450 nm for irradiation for 1 min-24 h to obtain the near-infrared light-responsive polyimide material.

[0030] Preferably, the organic solvent I is at least one selected from the group consisting of tetrahydrofuran, dioxane, toluene, chloroform, acetone, ethylene glycol dimethyl ether, acetonitrile, nitrobenzene, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, phenol, p-chlorophenol, o-dichlorobenzene, 1,2,4-trichlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, gamma-butyrolactone and ethyl acetate.

[0031] Preferably, the organic solvent II is at least one selected from the group consisting of tetrahydrofuran, dioxane, chloroform, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, phenol, p-chlorophenol, o-dichlorobenzene, 1,2,4-trichlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, gamma-butyrolactone and ethyl acetate.

[0032] Preferably, the structure of the imide ring-containing dimercapto monomer is ; the structure of the imide ring-containing dialkynyl monomer is ; wherein, the X represents an aromatic ring or an aliphatic ring element.

[0033] Preferably, the X represents any one of the following structural formulae:

[0034] , , ,

[0035] , , ,

[0036] .

[0037] The imide ring-containing dimercapto monomer and the imide ring-containing dialkynyl monomer can be obtained by purchase or self-preparation, and can be prepared by referring to the method disclosed in Chinese Patent Application CN202410768982.2.

[0038] Preferably, the thickness of the near-infrared light responsive polyimide material of the present application is 3-500 μm.

[0039] The present application also provides the application of the near-infrared light responsive polyimide material in optical drives, sensors, artificial muscles or soft robots.

[0040] The present application has the following beneficial effects:

[0041] The present application designs a photothermal molecule with a donor-acceptor-donor (D-A-D) configuration, which has the following advantages: 1. The photothermal molecule can effectively promote intramolecular charge transfer (ICT) and form a twisted intramolecular charge transfer (TICT) state, thereby significantly broadening and red-shifting the absorption and emission spectra of the molecule; 2. More importantly, the photothermal molecule has high non-radiative transition ability, which lays a structural foundation for excellent photothermal conversion performance; 3. The introduction of alkyl chains in the molecular structure not only improves the solubility of the molecule in various solvents, but also effectively reduces the close packing between molecules through the steric hindrance effect when the molecule aggregates; 4. This design ensures that even in the aggregated state, the molecule still has sufficient free space for active intramolecular motion (such as rotation and vibration), thereby effectively releasing the absorbed light energy in the form of heat energy; 5. The carbon-carbon double bond in the molecular structure provides efficient free motion activity structure for the two connected parts, ensuring that each part of the molecule can fully rotate / vibrate in the aggregated state, thereby having high photothermal performance.

[0042] The photothermal molecule of the present application is suitable for preparing a light-responsive polyimide material, which can not only avoid the agglomeration phenomenon of inorganic particles doped in the polymer, well maintain the mechanical properties of the original polymer, but also realize the high-efficiency non-radiative transition ability of the photothermal molecule in the polymer. The obtained light-responsive polyimide material has extremely fast response speed to infrared light and realizes reversible response. When the near-infrared light is irradiated, the material can immediately produce a sharp deformation (the response bending deformation is ≥155° within 1s, and the deformation is enough to lift the weight placed above), and can almost restore to the original shape after the near-infrared light is turned off.

[0043] The present application realizes the preparation of high-performance near-infrared light-responsive polyimide material, which has great application prospect in the field of soft robots and other frontier fields. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The proton nuclear magnetic resonance spectrum characterization of the near-infrared photothermal molecule obtained in Example 1 is shown in the following table:

[0045] Figure 2 The mass spectrum characterization of the near-infrared photothermal molecule obtained in Example 1 is shown in the following table:

[0046] Figure 3 The emission spectrum of the near-infrared photothermal molecule obtained in Example 1 in different proportions of tetrahydrofuran and water mixed solvents, and the change of fluorescence intensity and wavelength after adding poor solvent water are shown in the following table:

[0047] Figure 4 The photo of the near-infrared light-responsive polyimide material is shown in the following figure:

[0048] Figure 5 The light response schematic diagram of the near-infrared light-responsive polyimide material in Application Example 1 is shown in the following figure:

[0049] Figure 6 The schematic diagram of the near-infrared light-responsive polyimide material lifting the weight in Application Example 1 is shown in the following figure. DETAILED DESCRIPTION

[0050] The following examples are provided to better further understand the present application, and do not limit the best embodiments described, and do not constitute a limitation on the content and protection scope of the present application. Any person under the inspiration of the present application or the combination of the present application with other prior art features can obtain any product same or similar to the present application, which falls within the protection scope of the present application.

[0051] The specific experimental steps or conditions are not specified in the examples, which can be operated according to the conventional experimental steps described in the literature in the art or the operation or conditions. The reagents or instruments used are not specified by the manufacturer, which are conventional reagent products that can be obtained by market purchase.

[0052] Unless otherwise specified, room temperature or normal temperature in the embodiments of the present invention refers to 25±3℃.

[0053] Compound i ( , where -C 10 H 21 -C8H 17 (All of which represent straight-chain alkyl groups): prepared according to the method disclosed in Chinese patent application CN202510199792.8.

[0054] Compound ii ( Among them, -C6H 13 (Referring to straight-chain alkyl): It was prepared according to the method disclosed in Chinese patent application CN202510199792.8.

[0055] Compound iii ( ): Prepared according to the method disclosed in Chinese patent application CN202510199792.8.

[0056] Compound IV ( , where -C 14 H 29 (Referring to straight-chain alkyl): It was prepared according to the method disclosed in Chinese patent application CN202510199792.8.

[0057] Dithiomeridium monomer i ( 4.4424 g of 4,4'-(hexafluoroisopropene)phthalic anhydride was added in one batch to a three-necked flask equipped with a water separator and a reflux condenser. 121 g of acetic acid was added under an argon atmosphere, and mechanical stirring was started. 2.5038 g of p-aminothiophenol and 25 mL of cyclohexane were added sequentially, and the system was heated to reflux. After reflux for 4 h, the mixture was slowly cooled to 25 °C. The reaction solution was poured into distilled water, filtered, and the filter cake was washed three times with distilled water. The filter cake was dried in a vacuum oven at 80 °C for 24 h to obtain dimercaptomonomer i (yield 94%).

[0058] Dithiol monomer ii ( 6.6845 g of N,N'-(2,2-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diyl)bis(1,3-dioxy-1,3-dihydroisobenzofuran-5-carboxyamide) was added in one batch to a three-necked flask equipped with a water separator and a reflux condenser. 121 g of acetic acid was added under an argon atmosphere, and mechanical stirring was started. 2.5038 g of p-aminothiophenol and 25 mL of cyclohexane were added sequentially, and the system was heated to reflux. After reflux for 6 h, the mixture was slowly cooled to 25 °C. The reaction solution was poured into distilled water, filtered, and the filter cake was washed three times with distilled water. The filter cake was dried in a vacuum oven at 80 °C for 24 h to obtain the dimercapto monomer ii (yield 96%).

[0059] diacetylene monomer i : 6.6845 g of N,N'-(2,2-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diyl)bis(1,3- dioxo-1,3-dihydroisobenzofuran-5-carboxamide) was added at once into a three- necked flask equipped with a water separator and a condenser reflux device, 121 g of acetic acid was added under argon atmosphere and mechanical stirring was started, 2.3430 g of m- aminophenylacetylene and 25 mL of cyclohexane were added in sequence and the system was heated to reflux. After 6 h of reflux reaction, the system was slowly cooled to 25 °C, the reaction mixture was poured into distilled water, suction filtration was performed and the filter cake was washed three times with distilled water. The filter cake was dried in a vacuum oven at 80 °C for 24 h to obtain diacetylene monomer i (yield 91 %).

[0060] diacetylene monomer ii : 4.4424 g of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride was added at once into a three-necked flask equipped with a water separator and a condenser reflux device, 121 g of acetic acid was added under argon atmosphere and mechanical stirring was started, 2.3430 g of m- aminophenylacetylene and 25 mL of cyclohexane were added in sequence and the system was heated to reflux. After 6 h of reflux reaction, the system was slowly cooled to 25 °C, the reaction mixture was poured into distilled water, suction filtration was performed and the filter cake was washed three times with distilled water. The filter cake was dried in a vacuum oven at 80 °C for 24 h to obtain diacetylene monomer ii (yield 90 %).

[0061] Example 1

[0062] A method for preparing a near-infrared photothermal molecule, comprising the following steps:

[0063]

[0064] Compound i (100 mg, 0.08 mmol), 4-(4-bromostyryl)-N,N-di-p-tolyl aniline (182 mg, 0.40 mmol), sodium tert-butoxide (53.6 mg, 0.56 mmol), 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl (18.2 mg, 0.04 mmol), tris(dibenzylideneacetone)dipalladium(0) (9.2 mg, 0.01 mmol) were dissolved in toluene and refluxed at 120 °C for 12 h under nitrogen atmosphere. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, and washed with brine three times. Subsequently, the mixture was dried over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography using dichloromethane and petroleum ether (2:1) as the eluent to obtain the product near-infrared photothermal molecule A with a yield of 55%.

[0065] Figure 1The proton nuclear magnetic resonance spectrum of the near-infrared two-region photothermal molecule A obtained in Example 1 is characterized, which is consistent with the designed molecule, proving the successful preparation of the molecule.

[0066] Figure 2 The mass spectrum of the near-infrared two-region photothermal molecule A obtained in Example 1 is characterized.

[0067] Figure 3 The emission spectrum of the near-infrared two-region photothermal molecule A obtained in Example 1 in tetrahydrofuran solvent and the change of fluorescence intensity and wavelength after adding poor solvent water can be seen. The emission wavelength of the molecule in tetrahydrofuran is 900-1400 nm.

[0068] Example 2

[0069] A preparation method of a near-infrared photothermal molecule, which is only different from Example 1 in that the deprotonating agent is potassium tert-butoxide (62.8 mg, 0.56 mmol), and the remaining steps are the same as those of Example 1.

[0070] The product near-infrared photothermal molecule A is prepared, and the yield is 50%.

[0071] Example 3

[0072] A preparation method of a near-infrared photothermal molecule, which is only different from Example 1 in that the deprotonating agent is potassium tert-butoxide (62.8 mg, 0.56 mmol), and the remaining steps are the same as those of Example 1.

[0073] The product near-infrared photothermal molecule A is prepared, and the yield is 46%.

[0074] Example 4

[0075] A preparation method of a near-infrared photothermal molecule, which is only different from Example 1 in that the deprotonating agent is potassium tert-butoxide (62.8 mg, 0.56 mmol), and the remaining steps are the same as those of Example 1.

[0076] The product near-infrared photothermal molecule A is prepared, and the yield is 49%.

[0077] Example 5

[0078]

[0079] The difference from Example 1 is that compound i is replaced by an equal molar mass of compound ii, and 4-(4-bromostyryl)-N,N-di-p-tolyl aniline is replaced by an equal molar mass of p-bromo-(E)-3-chloropropenylbenzene. Other process steps and parameters are the same as in Example 1, and product near-infrared photothermal molecule B is prepared with a yield of 45%.

[0080] Example 6

[0081]

[0082] The difference from Example 1 is that compound i is replaced by an equal molar mass of compound iii, and 4-(4-bromostyryl)-N,N-di-p-tolyl aniline is replaced by an equal molar mass of 4-bromo-stilbene. Other process steps and parameters are the same as in Example 1, and product near-infrared photothermal molecule C is prepared with a yield of 52%.

[0083] Example 7

[0084]

[0085] The difference from Example 1 is that compound i is replaced by an equal molar mass of compound iv, and 4-(4-bromostyryl)-N,N-di-p-tolyl aniline is replaced by an equal molar mass of (E)-p-bromostyryl-substituted triphenylamine. Other process steps and parameters are the same as in Example 1, and product near-infrared photothermal molecule D is prepared with a yield of 58%.

[0086] Application Example 1

[0087] A preparation method of a near-infrared light responsive polyimide material, comprising the following steps:

[0088] Into a reaction vessel equipped with mechanical stirring, 0.6586 g of dimercaptan monomer i, 0.6425 g of diacetylenic monomer i and 9 mL of tetrahydrofuran were sequentially added, and stirred at 25°C for 15 min under nitrogen atmosphere. After the reaction was completed, the reaction solution was poured into methanol to precipitate fibrous solid product, which was filtered and the filter cake was washed with methanol for 3 times, and the filter cake was dried in a vacuum oven at 80°C for 20 h to obtain polyimide A.

[0089] 0.20 g of polyimide A was dissolved in 5 g of N,N-dimethylformamide, 0.1 mg of photothermal molecule A was dissolved in 2 g of dichloromethane, the two solutions were mixed uniformly, filtered through a four-fluorine filter with a pore size of 220 nm, and cast on a glass plate previously adjusted to be horizontal. The glass plate was treated in a vacuum oven at 60°C for 72 h, and after the temperature dropped to 25°C, the glass plate was taken out, the film was taken off after being soaked in deionized water for 2.5 h, and vacuum dried at 150°C for 24 h to obtain a photothermal molecule-doped polyimide film.

[0090] The polyimide film was placed under a 100 mW / cm 2 of 365 nm ultraviolet light for 20 min to obtain a near-infrared light responsive polyimide material I.

[0091] Figure 5 is a schematic diagram of the near-infrared light response of the polyimide material. The near-infrared light responsive polyimide material sample (specification: thickness 10 microns; length 2.5 centimeters, width 0.5 centimeters) of application example 1 was placed under 808 nm near-infrared light, and it was observed that it rapidly deformed and bent about 180° in 1 second, and after the near-infrared light was turned off, it almost returned to the original shape, and this process was reversible, indicating that the polyimide material of the application can respond to near-infrared light to achieve reversible driving.

[0092] Figure 6 is a schematic diagram of the polyimide material lifting the weight. A weight about 20 times the weight of the material was placed above the sample, and under 808 nm near-infrared light, it was observed that the sample rapidly deformed and lifted the weight, indicating that the near-infrared light responsive polyimide material of the application has excellent mechanical properties.

[0093] Application Example 2

[0094] A method for preparing a near-infrared light responsive polyimide material, which is only different from application example 1 in that the reaction monomers of the polyimide are 0.6586 g of dimercaptan monomer ii and 0.6425 g of diacetylene monomer i, and the remaining steps are the same as in application example 1. Near-infrared light responsive polyimide material II was prepared.

[0095] The near-infrared light responsive polyimide material sample of application example 2 was placed under 808 nm near-infrared light, and it was observed that it bent about 170° in 1 second, and after the near-infrared light was turned off, it almost returned to the original shape, and this process was reversible.

[0096] Application Example 3

[0097] A preparation method of a near-infrared light responsive polyimide material, which is different from application example 1 only in that the reaction monomers of the polyimide use 0.6586 g of the dimercapto monomer i and 0.6425 g of the dialkynyl monomer ii, and the remaining steps are the same as those of application example 1. A near-infrared light responsive polyimide material III is prepared.

[0098] The application example 3 near-infrared light responsive polyimide material sample is placed under 808 nm near-infrared light, and it can be seen that it bends about 175° in 1 second, and almost restores to the original form after the near-infrared light is turned off, and this process is reversible.

[0099] Application Example 4

[0100] A preparation method of a near-infrared light responsive polyimide material, which is different from application example 1 only in that the reaction monomers of the polyimide use 0.6586 g of the dimercapto monomer i and 0.6425 g of the dialkynyl monomer ii, and the remaining steps are the same as those of application example 1. A near-infrared light responsive polyimide material III is prepared.

[0101] The application example 4 near-infrared light responsive polyimide material sample is placed under 808 nm near-infrared light, and it can be seen that it bends about 180° in 1 second, and almost restores to the original form after the near-infrared light is turned off, and this process is reversible.

[0102] Application Example 5

[0103] A preparation method of a near-infrared light responsive polyimide material, which is different from application example 1 only in that the photothermal molecule A is replaced by the photothermal molecule B, and the remaining steps are the same as those of application example 1. A near-infrared light responsive polyimide material V is prepared.

[0104] The application example 5 near-infrared light responsive polyimide material sample is placed under 808 nm near-infrared light, and it can be seen that it bends about 160° in 1 second, and almost restores to the original form after the near-infrared light is turned off, and this process is reversible.

[0105] Application Example 6

[0106] A preparation method of a near-infrared light responsive polyimide material, which is different from application example 1 only in that the photothermal molecule A is replaced by the photothermal molecule C, and the remaining steps are the same as those of application example 1. A near-infrared light responsive polyimide material VI is prepared.

[0107] The application example 6 near-infrared light responsive polyimide material sample is placed under 808 nm near-infrared light, and it can be seen that it bends about 155° in 1 second, and almost restores to the original form after the near-infrared light is turned off, and this process is reversible.

[0108] Application Example 7

[0109] A preparation method of a near-infrared light responsive polyimide material, which is only different from application example 1 in that the photothermal molecule A is replaced by the photothermal molecule D, and the remaining steps are the same as application example 1. The near-infrared light responsive polyimide material VII is prepared.

[0110] The application example 7 near-infrared light responsive polyimide material sample is placed under the near-infrared light of 808 nm, and it can be seen that it bends about 180° in 1 second, and almost restores to the original form after the near-infrared light is turned off, and this process is reversible.

[0111] Comparative application example

[0112] The NDI-1 molecule is prepared according to the method disclosed in Chinese patent application CN202510199792.8.

[0113]

[0114] A preparation method of a near-infrared light responsive polyimide material, which is only different from application example 1 in that the photothermal molecule A is replaced by the NDI-1 molecule, and the remaining steps are the same as application example 1. The near-infrared light responsive polyimide material VIII is prepared.

[0115] The application example 7 near-infrared light responsive polyimide material sample is placed under the near-infrared light of 808 nm, and it can be seen that it bends about 180° in 1 second, and almost restores to the original form after the near-infrared light is turned off, and this process is reversible.

[0116] As can be seen from the above, the photothermal molecule designed by the application is particularly suitable for preparing a light-responsive polyimide material, which not only can avoid the agglomeration phenomenon of inorganic particles doped in the polymer, well maintaining the mechanical properties of the original polymer, but also realizes the high-efficiency non-radiative transition ability of the photothermal molecule in the polymer. The obtained light-responsive polyimide material has extremely fast response speed to infrared light and realizes reversible response. When irradiated by near-infrared light, it immediately produces a sharp deformation (bends ≥155° in 1s, and the deformation is sufficient to lift the weight placed above), and almost restores to the original form after the near-infrared light is turned off.

[0117] The application realizes the preparation of a high-performance near-infrared light responsive polyimide material, and has great application prospect in the fields of soft robots and other frontiers.

[0118] The above description is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto. Any changes or replacements within the technical range disclosed in the application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A near-infrared photothermal molecule, characterized in that, The structure is shown in the following formula: ； R1, R2are each independently selected from one of a linear alkyl group of C5-C 20 a branched alkyl group of C5-C 20 a cyclic alkyl group of C5-C 20 a cyclic alkyl group of C5-C R3, R4, R5, R6are each independently selected from the group consisting of C1-C 30 haloalkyl, phenyl, triphenylamine, hydrogen atom is substituted by one or more C1-C 20 one of alkyl-substituted triphenylamine.

2. The near infrared photothermal molecule of claim 1, wherein, is selected from the following structures: 、 、 、 、 、 、 。 3. The method of preparing a near-infrared photothermal molecule according to any one of claims 1-2, characterized in that, The method comprises the following steps: dissolving a compound , , a deprotonating agent, a ligand and a catalyst in an organic solvent, mixing and carrying out a reflux reaction, and carrying out post-treatment after the reaction is completed, so that the near-infrared photothermal molecule is obtained. R1, R2are each independently selected from one of a linear alkyl group of C5-C 20 20 a branched alkyl group of C5-C 20 a cyclic alkyl group of C5-C​ said R' is selected from C1-C 30 haloalkyl, phenyl, triphenylamine, hydrogen atom substituted with one or more C1-C 20 alkyl; and one of the following: haloalkyl, phenyl, triphenylamine, hydrogen atom substituted with one or more C1-C The deprotonating agent is sodium tert-butoxide or potassium tert-butoxide; The ligand is tri-tert-butylphosphine tetrafluoroborate, 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl or 2-dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl; The catalyst is tris(dibenzylideneacetone)dipalladium(0) or palladium acetate.

4. Use of the near-infrared photothermal molecule according to any one of claims 1-2 in a photoresponsive polyimide material.

5. A near-infrared light responsive polyimide material, characterized by, The near-infrared photothermal molecule according to any one of claims 1-2; The preparation method of the near-infrared photoresponsive polyimide material comprises the following steps: The imide ring-containing dimercapto monomer and the imide ring-containing dialkynyl monomer are dissolved in an organic solvent I, and then reacted at 20-80 ℃ for 10-360 min under a nitrogen atmosphere. After the reaction is completed, the reaction solution is introduced into methanol to precipitate a fibrous solid product. The product is filtered, washed and dried to obtain a polyimide. The near-infrared photothermal molecule is dissolved in an organic solvent I, and the polyimide is dissolved in an organic solvent II. After the two solutions are mixed and filtered through a four-fluorine filter core, they are cast or spin-coated on a substrate. The substrate is then treated in a vacuum oven at 60-120 ℃ for 48-72 h to obtain a polyimide film doped with a photothermal molecule. The polyimide film is irradiated under an ultraviolet lamp with a power density of 5 mW / cm 2 5 W / cm 2 , a wavelength of 10-450 nm for 1 min-24 h to obtain a near-infrared light responsive polyimide material. The organic solvent I is selected from at least one of tetrahydrofuran, dioxane, toluene, chloroform, acetone, ethylene glycol dimethyl ether, acetonitrile, nitrobenzene, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, phenol, p-chlorophenol, o-dichlorobenzene, 1,2,4-trichlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, gamma-butyrolactone and ethyl acetate. The organic solvent II is selected from at least one of tetrahydrofuran, dioxane, chloroform, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, phenol, p-chlorophenol, o-dichlorobenzene, 1,2,4-trichlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, gamma-butyrolactone, ethyl acetate; the structure of the di-mercapto monomer containing an imide ring is ; the structure of the di-alkynyl monomer containing an imide ring is ; wherein the X represents any one of the following structural formulae: 、 、 、 、 、 、 。 6. Use of the near-infrared photoresponsive polyimide material according to claim 5 in a light driver, a sensor, an artificial muscle or a soft robot.

Images